Generic Earthquake Simulator
|
|
- August Wilkerson
- 6 years ago
- Views:
Transcription
1 Generic Earthquake Simulator by Terry E. Tullis, Keith Richards-Dinger, Michael Barall, James H. Dieterich, Edward H. Field, Eric Heien, Louise H. Kellogg, Fred Pollitz, John Rundle, Michael Sachs, Donald L. Turcotte, Steven N. Ward, and Burak Yikilmaz 1 INTRODUCTION Many of the papers in this topical issue concern earthquake simulators and their results. The goals and history of the project leading to this work are described in the preface to this topical issue. Earthquake simulators are computer programs that use physics of stress transfer and frictional resistance to describe earthquake sequences. Some are capable of generating long earthquake histories on many faults. They necessarily adopt a variety of simplifications to make computation feasible. The amount of detail computed within individual earthquakes depends on the simulator. None of those capable of generating long histories includes elastodynamics, but some make approximations of it. Nevertheless, seismic waves are not computed in any of the many-fault simulators focused on here. The faults are typically approximated by many rectangular elements, although the future use of triangles would allow more accurate representation of curved fault surfaces. This paper briefly describes the features that are common to all of the earthquake simulators discussed in this topical issue of SRL. Following it are four papers (Pollitz, 2012; Richards- Dinger and Dieterich, 2012; Sachs et al., 2012; Ward, 2012) authored by each of the groups, which present features of their simulator that go beyond this generic description. Results from using these simulators are not presented in those papers but are contained within a subsequent paper (Tullis et al., 2012) that compares the results of using these five simulators on an all- California fault model, allcal2. A detailed description of this fault model can be found at eqsims/, and the formats used for input and output by our group are described by Barall (2012). EARTHQUAKE SIMULATOR INPUTS Fault Geometry and Slip Rates UCERF (Field et al., 2008) calls the combination of fault geometry and slip rates a deformation model, and these are the relatively well-known inputs to an earthquake simulator. Our current version of an all-california deformation model, allcal2 (excluding Cascadia), is nearly the same as UCERF2 (Field et al., 2008). In this volume, it is this deformation model that is used for the results (Tullis et al., 2012). In the future, we plan to use other versions of California fault models, such as the UCERF3 deformation model. Bulk Rheology For most of the simulators in this volume, the medium in which the fault system is embedded is represented by a homogeneous linear elastic half-space. However, one simulator (Pollitz, 2012), ViscoSim, can include both viscoelastic behavior and layered elasticity. Stresses Absolute levels of stress are generally not needed by these simulations, although ViscoSim (Pollitz, 2012) needs absolute levels to have realistic flow rates in the viscoelastic regions. The sources of the stresses on each fault element at any time can be divided into two different classes that are handled fundamentally differently by the simulators: (1) slip on the explicitly modeled fault elements (including the element itself ) and (2) all sources external to the fault model. The former are calculated by some appropriate boundary element method (e.g., Chinnery, 1963 or Okada, 1992). Sources of stress included in the latter class include far-field tectonic motions, possible viscoelastic flow in the lower crust and mantle (for simulators other than ViscoSim, which includes this source explicitly), and earthquakes that occur off of the explicitly modeled fault system. Even in the absence of any detailed knowledge of these external sources, simply enforcing that the stresses on the fault elements not diverge to infinity at long times and that the fault patches all slip on average at their prescribed long-term rates implies that the long-term averages of these external stressing rates must simply be equal to those that would result from slipping each fault element steadily at the negative of its prescribed long-term rate (Savage, 1983). Another way to think about backslip loading is that the stresses due to imposing backward slip on all the faults at their long-term rate eventually become large enough to make them slip forward, typically by earthquakes, to relax the stress. Thus, the simulators use the constant stressing rates that result from such a backslip calculation to represent the external sources of stress. Although the time averages of the external stressing rates will be correct with this method, it will miss possible time variations. 2 doi: / Seismological Research Letters Volume 83, Number 6 December
2 3 4 Fault Friction The various simulators use different constitutive descriptions for fault friction. In Earth, the frictional strengths of faults presumably vary from point to point, but we have insufficient knowledge of their actual values and spatial variations. Laboratory friction measurements provide some idea of possible in situ friction values as a function of rock type and temperature, but our knowledge of the actual rock types along faults is woefully inadequate for applying friction values to each point on a fault. Most of the earthquake simulators assume some difference between static and dynamic friction, and in some cases, these may vary with slip or slip velocity. One simulator (Richards-Dinger and Dieterich, 2012) uses rate and state friction. Although there is a tendency to refer to the highest stress level reached in an earthquake cycle in the simulations as the fault strength, all that is really modeled are changes in strength, namely, strength drops. Depending on the friction law used, the actual stress drop during an event could be somewhat smaller than the strength drop. Ideally we would know the appropriate variation in strength drop to use from one fault section to another, but we have insufficient information to determine this well. Typically in this work, for most faults, we use relations such as area magnitude scaling to estimate the stress drop associated with earthquakes of a typical size for each fault section and then set the strength drop equal to that. In the case of the simulator that does not specify a strength drop but uses rateand state-dependent friction (Richards-Dinger and Dieterich, 2012), the stress drop is proportional to the product of the normal stress σ n and the difference of the state and rate coefficients, a and b, that is, to σ n b a, and weakly (logarithmically) dependent on the recurrence time; thus, some experimentation with varying σ n and/or b a is required to produce a given average stress drop. In some places where paleoseismic data provide recurrence intervals, we tune the strength drops to match those data. Thus, for example, by trial and error, each simulator increases or decreases the assigned strength drop to lengthen or shorten, respectively, the simulated recurrence intervals to match those determined paleoseismically. Because different simulators assume different frictional behavior and treat rupture weakening differently, each simulator must do this tuning separately, although the tuning for each begins from a common assumed starting strength-drop distribution. EARTHQUAKE SIMULATOR OUTPUTS The output of an earthquake simulator may be quite varied and can include any desired statistical or other measure of what occurred as a function of time and space during a long history of simulated events. We have created a variety of tools to create standard output plots so that all the simulators can be compared via identical processing. Some such plots are shown by Tullis et al. (2012), but many more have been created and still more could be generated in the future. The tools themselves are written in the R language (e.g., R Development Core Team, 2012). They currently consist of several utility functions bundled together as an R package and 23 actual tools. Each tool is a stand-alone executable that can be called from the command line (via the Rscript mechanism), which reads in a simulator output file in the standard format (Barall, 2012), possibly reads in other files (e.g., a fault geometry file), performs some sort of analysis, and either generates a plot or writes an output file with the results of this analysis. Input filenames, output filenames, and parameters controlling the analysis are all specified via command-line arguments. As the simulator output files are ascii encoded, the initial parsing of these ascii files can dominate the run time of some of the tools. Thus, a parsed, binary version of the files can optionally be saved for faster loading by subsequent tools. Several examples of the kinds of plots produced by the tools are shown by Tullis et al. (2012) and include frequency magnitude distributions, various scaling plots (e.g., magnitude vs. area), and recurrence time probability density functions. In addition to being called individually, the tools can also be called jointly via a wrapper program called runtools. The behavior of runtools is controlled by a configuration file. In this file, sets of tool runs appropriate for various problem setups are defined so that an entire set of plots and output files can be produced for a given simulator output with a single command. In addition, runtools move a copy of the simulator output files (both the original standard ascii file and the parsed binary file) to an archive directory and place the output files in a directory accessible on the web. DIFFERENCES BETWEEN SIMULATORS Table 1 lists many of the differences between the simulators. A description of the meaning of the features listed in column 1 of the table follows. The first three rows refer to different aspects of how friction is treated by each simulator, this being the biggest difference between many of them. Rate and state friction (Dieterich, 1972, 1978, 1979, 1981; Ruina, 1983; Dieterich and Conrad, 1984; Tullis, 1986, 1988, 1996; Dieterich and Kilgore, 1994; Marone, 1998) is used by only one simulator. Among other features, it incorporates both a velocity and a displacement dependence to friction, but velocity dependence and displacement dependence can also be incorporated in simpler ways, as is done by some of our other simulators. Radiation damping (Rice, 1993) introduces a resistance to rapid slip and represents the inertial forces that retard rapid acceleration. Thus, although it does not involve seismic radiation, it realistically prevents slip speeds from becoming unbounded. Rupture weakening is a feature that promotes the propagation of ruptures by making it easier for fault elements to slip when neighboring elements slip. It is intended to create effects on rupture propagation that are similar to what would occur in fully elastodynamic treatments in which dynamic stress concentrations occur at the tip of propagating ruptures. Details of what occurs during an event, for example, the progression of the amount of slip during the event on each fault element that eventually slips, are resolved by some simulators and not by others. The temporal delay of slip along 2 Seismological Research Letters Volume 83, Number 6 December 1993
3 Table 1 Features of Each Earthquake Simulator Included in this Topical Issue of SRL See Text for Description of the Features ALLCAL VIRTCAL RSQSim ViscoSim Rate-state friction Velocity-dependent friction Displacement-dependent friction Radiation damping Rupture weakening Details during event Stress propagation delay Viscoelastic stress transfer Layered elasticity a rupture that would occur due to finite-wave velocities is included in only one of the simulators. Viscoelastic transfer of stress due to flow in deeper layers is only treated by one simulator. Including layers with differing elastic properties, instead of assuming only an elastic half-space, is only done for one simulator. It is notable that none of the simulators contain all of the features listed in Table 1, in part a result of the computational difficulties of including them all. Nevertheless, the fact that the simulators all do a reasonable job of matching the statistical behavior of observed seismicity (Tullis et al., 2012) suggests that for many purposes, including all of the known physics about earthquakes may not be necessary, especially when enough observational data exist to tune unknown parameters such as the spatial variations in strength drops. It should be noted that other more detailed earthquake simulators exist that presently are not suited for generating long histories of earthquakes on a specified geographic collection of many faults, but that make fewer approximations than do those simulators used in the comparisons in this topical issue of SRL. For example, three other simulators have been used to make comparisons of earthquake simulator results for simpler single fault problems in which it is possible to make more detailed comparison of what occurs (Richards-Dinger et al., 2008; Tullis et al., 2009). Notable among these other simulators is the one by Nadia Lapusta that uses an FFTapproach and includes both full elastodynamics and rate and state friction (Lapusta et al., 2000; Lapusta and Rice, 2003). Others include the one by Bruce Shaw that includes full elastodynamics in 2D (Shaw, 2003) and 3D (Shaw and Wesnousky, 2008) and PARK that uses rate and state friction, both in an early version (Stuart and Tullis, 1995; Tullis, 1996) and in a more recent one that uses radiation damping as well as a fast multipole method to increase computation efficiency (Tullis et al., 1999; Tullis, 2003; Tullis and Beeler, 2008). SUMMARY All of the simulators discussed in this topical issue of SRL use much of what is known about the physics of earthquakes and about the California fault geometry and slip rates, although true elastodynamics is not used, and off-fault seismicity is not currently included. More information is desirable about the faults than is known, especially how the stress drops associated with earthquakes vary from fault section to fault section. Consequently, estimates are made for stress drops in those places where information is lacking, and the constraint on them provided by paleoseismic recurrence interval data is used at locations where that is available. Each simulator makes a variety of simplifications to allow calculation of long earthquake histories on many faults. Representation of fault friction and whether or how to deal with approximations to elastodynamic behavior are among the differences between the simulators. The diversity of simulator assumptions and methods provides some idea of the influence that different assumptions have on the results, as is discussed by Tullis et al. (2012). ACKNOWLEDGMENTS We thank Hiroyuki Noda for a helpful and timely review and Jeanne Hardebeck for helpful comments. This research was supported by the Southern California Earthquake Center (SCEC). SCEC is funded by the National Science Foundation Cooperative Agreement EAR and U.S. Geological Survey Cooperative Agreement 07HQAG0008. The SCEC contribution number for this paper is REFERENCES Barall, M. (2012). Data transfer file formats for earthquake simulators, Seismol. Res. Lett. 83, XXXX XXXX. Dieterich, J. H. (1972). Time-dependent friction in rocks, J. Geophys. Res. 77, 3,690 3,697. Dieterich, J. H. (1978). Time-dependent friction and the mechanics of stick slip, Pure Appl. Geophys. 116, Dieterich, J. H. (1979). Modeling of rock friction, 1, Experimental results and constitutive equations, J. Geophys. Res. 84, 2,161 2,168. Dieterich, J. H. (1981). Constitutive properties of faults with simulated gouge, in Mechanical Behavior of Crustal Rocks, American Geophysical Monograph, Vol. 24, Dieterich, J. H., and G. Conrad (1984). Control of time- and velocitydependent friction in rocks by absorbed water, J. Geophys. Res. 89, 4,196 4, Seismological Research Letters Volume 83, Number 6 December
4 6 7 Dieterich, J. H., and B. D. Kilgore (1994). Direct observation of frictional contacts: new insights for state-dependent properties, Pure Appl. Geophys. 143, Field, E. H. et al (2008). The Uniform California Earthquake Rupture Forecast, Version 2 (UCERF2), U.S. Geol. Surv. Open-File Rept Lapusta, N., and J. R. Rice (2003). Nucleation and early seismic propagation of small and large events in a crustal earthquake model, J. Geophys. Res. 108, no. B4, doi: /2001JB Lapusta, N., J. Rice, Y. Ben-Zion, and G. Zheng (2000). Elastodynamic analysis for slow tectonic loading with spontaneous rupture episodes on faults with rate- and state-dependent friction, J. Geophys. Res. 105, 23,765 23,789. Marone, C. J. (1998). Laboratory-derived friction constitutive laws and their application to seismic faulting, Annu. Rev. Earth Planet. Sci. 26, Pollitz, F. (2012). ViscoSim earthquake simulator, Seismol. Res. Lett. 83, XXXX XXXX. Rice, J. R. (1993). Spatio-temporal complexity of slip on a fault, J. Geophys. Res. 98, 9,885 9,907. Richards-Dinger, K., and J. H. Dieterich (2012). RSQSim earthquake simulator, Seismol. Res. Lett. 83, XXXX XXXX. Richards-Dinger, K. et al (2008). Collaborative comparison of earthquake simulators, Eos Trans. AGU 89 (Fall Meet. Suppl.),Abstract No. S33A Ruina, A. L. (1983). Slip instability and state variable friction laws, J. Geophys. Res. 88, 10,359 10,370. Sachs, M., B. Yikilmaz, E. Heien, J. Rundle, D. L. Turcotte, and L. Kellogg (2012). Virtual California earthquake simulator, Seismol. Res. Lett. 83, XXXX XXXX. Savage, J. C. (1983). A dislocation model of strain accumulation and release at a subduction zone, J. Geophys. Res. 88, no. B6, 4,984 4,996, doi: /JB088iB06p Shaw, B. E. (2003). Magnitude dependence of radiated energy spectra: far-field expression of slip pulses in earthquake models, J. Geophys. Res. 108, 15, 2100, doi: /2001JB Shaw, B. E., and S. G. Wesnousky (2008). Slip-length scaling in large earthquakes: The role of deep penetrating slip below the seismogenic layer, Bull. Seismol. Soc. Am. 98, Stuart, W. D., and T. E. Tullis (1995). Fault model for preseismic deformation at Parkfield, California, J. Geophys. Res. 100, 24,079 24,099. Tullis, T. E. (1986). Friction and faulting, Pure Appl. Geophys. 124, 1 9. Tullis, T. E. (1988). Rock friction constitutive behavior from laboratory experiments and its implications for an earthquake prediction field monitoring program, Pure Appl. Geophys. 126, Tullis, T. E. (1996). Rock friction and its implications for earthquake prediction examined via models of Parkfield earthquakes, in Earthquake Prediction: The Scientific Challenge, L. Knopoff (Editor), Proceedings of the National Academy of Science U.S.A., 3,803 3,810. Tullis, T. E. (2003). Earthquake models using rate and state friction and fast multipoles, Geophys. Res. Abstr. 5, 13,211. Tullis, T. E., and N. M. Beeler (2008). Multiscale earthquake simulator, using rate and state friction and fast multipoles, focused on Parkfield, California, Eos Trans. AGU 89 (Fall Meet. Suppl.), Abstract No. S32A-08. Tullis, T. E., H. Noda, K. Richards-Dinger, N. Lapusta, J. H. Dieterich, Y. Kaneko, and N. M. Beeler (2009). Comparing earthquake simulators that include rate and state friction, Eos Trans. AGU 90 (Fall Meet. Suppl.), Abstract No. T21B Tullis, T. E., K. Richards-Dinger, M. Barall, J. H. Dieterich, E. H. Field, E. Heien, L. H. Kellogg, F. Pollitz, J. Rundle, M. Sachs, D. L. Turcotte, S. N. Ward, and B. Yikilmaz (2012). Comparison among observations and earthquake simulator results for the allcal2 California fault model, Seismol. Res. Lett. 83, XXXX XXXX. Tullis, T. E., J. Salmon, N. Kato, and M. Warren (1999). The application of fast multipole methods to increase the efficiency of a single-fault numerical earthquake model, Eos Trans. AGU, 80 (Fall Meet. Suppl.), F924. Ward, S. N. (2012). ALLCAL earthquake simulator, Seismol. Res. Lett. 83, XXXX XXXX. Terry E. Tullis Brown University Department of Geological Sciences Providence, Rhode Island U.S.A. Terry_Tullis@brown.edu Keith Richards-Dinger UCR Michael Barall Invisible Software James H. Dieterich UCR Edward H. Field USGS Eric Heien Louise H. Kellogg Fred Pollitz USGS John Rundle Michael Sachs Donald L. Turcotte Steven N. Ward UCSC Burak Yikilmaz 4 Seismological Research Letters Volume 83, Number 6 December 1993
5 QUERIES 1. AU: Please provide the complete postal addresses of affiliations 2 to AU: References Chinnery (1963) and Okada (1992) are cited in the text but not provided in the reference list. Please provide publication details or delete these citations. 3. AU: Do the asterisks represent (1) multiplication (so would be replaced by a multiplication sign), (2) convolution in cross correlation (where the asterisk would be centered), or (3) a complex conjugate of a complex number (where the asterisk would be set as a superscript)? 4. AU: R Development Core Team (2012): Please provide publication details for this citation in the reference list. 5. Dieterich (1981): Please provide the editors name. 6. AU: Field et al. (2008): As per style et al. should not be used. Please provide all author names. Also provide page count if applicable. 7. AU: Richards-Dinger et al. (2008): Please provide all authors name. Seismological Research Letters Volume 83, Number 6 December
Numerical simulation of seismic cycles at a subduction zone with a laboratory-derived friction law
Numerical simulation of seismic cycles at a subduction zone with a laboratory-derived friction law Naoyuki Kato (1), Kazuro Hirahara (2) and Mikio Iizuka (3) (1) Earthquake Research Institute, University
More informationEffect of an outer-rise earthquake on seismic cycle of large interplate earthquakes estimated from an instability model based on friction mechanics
Effect of an outer-rise earthquake on seismic cycle of large interplate earthquakes estimated from an instability model based on friction mechanics Naoyuki Kato (1) and Tomowo Hirasawa (2) (1) Geological
More informationSimulated and Observed Scaling in Earthquakes Kasey Schultz Physics 219B Final Project December 6, 2013
Simulated and Observed Scaling in Earthquakes Kasey Schultz Physics 219B Final Project December 6, 2013 Abstract Earthquakes do not fit into the class of models we discussed in Physics 219B. Earthquakes
More informationSeismic and aseismic processes in elastodynamic simulations of spontaneous fault slip
Seismic and aseismic processes in elastodynamic simulations of spontaneous fault slip Most earthquake simulations study either one large seismic event with full inertial effects or long-term slip history
More informationRate and State-Dependent Friction in Earthquake Simulation
Rate and State-Dependent Friction in Earthquake Simulation Zac Meadows UC Davis - Department of Physics Summer 2012 REU September 3, 2012 Abstract To better understand the spatial and temporal complexity
More informationVariability of earthquake nucleation in continuum models of rate-and-state faults and implications for aftershock rates
Click Here for Full Article JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 113,, doi:10.1029/2007jb005154, 2008 Variability of earthquake nucleation in continuum models of rate-and-state faults and implications
More informationOn the nucleation of creep and the interaction between creep and seismic slip on rate- and state-dependent faults
Click Here for Full Article GEOPHYSICAL RESEARCH LETTERS, VOL. 34, L15303, doi:10.1029/2007gl030337, 2007 On the nucleation of creep and the interaction between creep and seismic slip on rate- and state-dependent
More informationHitoshi Hirose (1), and Kazuro Hirahara (2) Abstract. Introduction
Three dimensional simulation for the earthquake cycle at a subduction zone based on a rate- and state-dependent friction law: Insight into a finiteness and a variety of dip-slip earthquakes Hitoshi Hirose
More informationIntroduction: Advancing Simulations of Sequences of Earthquakes and Aseismic Slip (SEAS)
Introduction: Advancing Simulations of Sequences of Earthquakes and Aseismic Slip (SEAS) Brittany Erickson (Portland State University) Junle Jiang (University of California, San Diego) SCEC DR-SEAS Workshop,
More information3D MODELING OF EARTHQUAKE CYCLES OF THE XIANSHUIHE FAULT, SOUTHWESTERN CHINA
3D MODELING OF EARTHQUAKE CYCLES OF THE XIANSHUIHE FAULT, SOUTHWESTERN CHINA Li Xiaofan MEE09177 Supervisor: Bunichiro Shibazaki ABSTRACT We perform 3D modeling of earthquake generation of the Xianshuihe
More informationEFFECTS OF NON-LINEAR WEAKENING ON EARTHQUAKE SOURCE SCALINGS
Extended abstract for the 11th International Conference on Fracture 2005 1 EFFECTS OF NON-LINEAR WEAKENING ON EARTHQUAKE SOURCE SCALINGS J.-P. Ampuero Geosciences Department, Princeton University, USA
More informationDepth variation of coseismic stress drop explains bimodal earthquake magnitude-frequency distribution
Click Here for Full Article GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L24301, doi:10.1029/2008gl036249, 2008 Depth variation of coseismic stress drop explains bimodal earthquake magnitude-frequency distribution
More informationModeling Approaches That Reproduce a Range of Fault Slip Behaviors: What We Have and What We Need Nadia Lapusta. California Institute of Technology
Modeling Approaches That Reproduce a Range of Fault Slip Behaviors: What We Have and What We Need Nadia Lapusta California Institute of Technology Modeling Approaches That Reproduce a Range of Fault Slip
More informationScaling of small repeating earthquakes explained by interaction of seismic and aseismic slip in a rate and state fault model
Click Here for Full Article JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 114,, doi:10.1029/2008jb005749, 2009 Scaling of small repeating earthquakes explained by interaction of seismic and aseismic slip in a
More informationScenario Earthquake and Tsunami Simulations for a Pacific Rim GNSS Tsunami Early Warning System
Scenario Earthquake and Tsunami Simulations for a Pacific Rim GNSS Tsunami Early Warning System Kasey Schultz February 2, 2015 Abstract The first operational prototype for a Pacific Rim Tsunami Early Warning
More informationGround displacement in a fault zone in the presence of asperities
BOLLETTINO DI GEOFISICA TEORICA ED APPLICATA VOL. 40, N. 2, pp. 95-110; JUNE 2000 Ground displacement in a fault zone in the presence of asperities S. SANTINI (1),A.PIOMBO (2) and M. DRAGONI (2) (1) Istituto
More informationCoulomb stress changes due to Queensland earthquakes and the implications for seismic risk assessment
Coulomb stress changes due to Queensland earthquakes and the implications for seismic risk assessment Abstract D. Weatherley University of Queensland Coulomb stress change analysis has been applied in
More informationSynthetic Seismicity Models of Multiple Interacting Faults
Synthetic Seismicity Models of Multiple Interacting Faults Russell Robinson and Rafael Benites Institute of Geological & Nuclear Sciences, Box 30368, Lower Hutt, New Zealand (email: r.robinson@gns.cri.nz).
More informationOverview of the PyLith Finite Element Code
Overview of the PyLith Finite Element Code www.geodynamics.org Charles Williams (GNS Science) Brad Aagaard (USGS) Matt Knepley (University of Chicago) CIG Software PyLith is a Tool for Crustal Deformation
More informationFrictional rheologies have a wide range of applications in engineering
A liquid-crystal model for friction C. H. A. Cheng, L. H. Kellogg, S. Shkoller, and D. L. Turcotte Departments of Mathematics and Geology, University of California, Davis, CA 95616 ; Contributed by D.
More informationSimulation of earthquake rupture process and strong ground motion
Simulation of earthquake rupture process and strong ground motion Takashi Miyatake (1) and Tomohiro Inoue (2) (1) Earthquake Research Institute, University of Tokyo, Yayoi, Bunkyo, Tokyo, 113-0032, Japan
More informationSlip-weakening behavior during the propagation of dynamic ruptures obeying rate- and state-dependent friction laws
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. B8, 2373, doi:10.1029/2002jb002198, 2003 Slip-weakening behavior during the propagation of dynamic ruptures obeying rate- and state-dependent friction laws
More informationMegathrust Earthquakes
Megathrust Earthquakes Susan Schwartz University of California Santa Cruz CIDER 2017 UC Berkeley July 5, 2017 The largest megathrust events are not uniformally distributed at all subduction zones. M>8
More informationDi#erences in Earthquake Source and Ground Motion Characteristics between Surface and Buried Crustal Earthquakes
Bull. Earthq. Res. Inst. Univ. Tokyo Vol. 2+,**0 pp.,/3,00 Di#erences in Earthquake Source and Ground Motion Characteristics between Surface and Buried Crustal Earthquakes Paul Somerville* and Arben Pitarka
More informationFRICTIONAL HEATING DURING AN EARTHQUAKE. Kyle Withers Qian Yao
FRICTIONAL HEATING DURING AN EARTHQUAKE Kyle Withers Qian Yao Temperature Change Along Fault Mode II (plain strain) crack rupturing bilaterally at a constant speed v r Idealize earthquake ruptures as shear
More informationScale Dependence in the Dynamics of Earthquake Rupture Propagation: Evidence from Geological and Seismological Observations
Euroconference of Rock Physics and Geomechanics: Natural hazards: thermo-hydro-mechanical processes in rocks Erice, Sicily, 25-30 September, 2007 Scale Dependence in the Dynamics of Earthquake Rupture
More informationFriction. Why friction? Because slip on faults is resisted by frictional forces.
Friction Why friction? Because slip on faults is resisted by frictional forces. We first describe the results of laboratory friction experiments, and then discuss the implications of the friction constitutive
More informationHeterogeneous Coulomb stress perturbation during earthquake cycles in a 3D rate-and-state fault model
Click Here for Full Article GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L21306, doi:10.1029/2008gl035614, 2008 Heterogeneous Coulomb stress perturbation during earthquake cycles in a 3D rate-and-state fault
More informationFault Representation Methods for Spontaneous Dynamic Rupture Simulation. Luis A. Dalguer
Fault Representation Methods for Spontaneous Dynamic Rupture Simulation Luis A. Dalguer Computational Seismology Group Swiss Seismological Service (SED) ETH-Zurich July 12-18, 2011 2 st QUEST Workshop,
More informationSpectral Element simulation of rupture dynamics
Spectral Element simulation of rupture dynamics J.-P. Vilotte & G. Festa Department of Seismology, Institut de Physique du Globe de Paris, 75252 France ABSTRACT Numerical modeling is an important tool,
More informationDoes Aftershock Duration Scale With Mainshock Size?
GEOPHYSICAL RESEARCH LETTERS, VOL.???, NO., PAGES 1 16, Does Aftershock Duration Scale With Mainshock Size? A. Ziv A. Ziv, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel. (e-mail: zival@bgu.ac.il)
More informationThe 3 rd SCEC CSM workshop
The 3 rd SCEC CSM workshop Welcome on behalf of the organizers Jeanne Hardebeck Brad Aagaard David Sandwell Bruce Shaw John Shaw Thorsten Becker Thanks for playing! SCEC Community Stress Model (CSM) Community
More informationOriginally published as:
Originally published as: Lorenzo Martín, F., Wang, R., Roth, F. (2002): The effect of input parameters on visco-elastic models of crustal deformation. - Física de la Tierra, 14, 33-54 The effect of input
More informationProbabilities for Jumping Fault Segment Stepovers
GEOPHYSICAL RESEARCH LETTERS, VOL.???, XXXX, DOI:1.129/, Probabilities for Jumping Fault Segment Stepovers Bruce E. Shaw Lamont-Doherty Earth Observatory, Columbia University, New York James H. Dieterich
More informationVerification of the asperity model using seismogenic fault materials Abstract
Verification of the asperity model using seismogenic fault materials Takehiro Hirose*, Wataru Tanikawa and Weiren Lin Kochi Institute for Core Sample Research/JAMSTEC, JAPAN * Corresponding author: hiroset@jamstec.go.jp
More informationAfterslip, slow earthquakes and aftershocks: Modeling using the rate & state friction law
Afterslip, slow earthquakes and aftershocks: Modeling using the rate & state friction law Agnès Helmstetter (LGIT Grenoble) and Bruce Shaw (LDE0 Columbia Univ) Days after Nias earthquake Cumulative number
More informationGeophysical Journal International
Geophysical Journal International Geophys. J. Int. (212) 189, 1797 186 doi: 1.1111/j.1365-246X.212.5464.x A new paradigm for simulating pulse-like ruptures: the pulse energy equation Ahmed E. Elbanna 1
More informationThe Mechanics of Earthquakes and Faulting
The Mechanics of Earthquakes and Faulting Christopher H. Scholz Lamont-Doherty Geological Observatory and Department of Earth and Environmental Sciences, Columbia University 2nd edition CAMBRIDGE UNIVERSITY
More information2018 Blue Waters Symposium June 5, Southern California Earthquake Center
Integrating Physics-based Earthquake Cycle Simulator Models and High-Resolution Ground Motion Simulations into a Physics-based Probabilistic Seismic Hazard Model PI: J. Vidale; Former PI: T. H. Jordan
More informationImprovement in the Fault Boundary Conditions for a Staggered Grid Finite-difference Method
Pure appl. geophys. 63 (6) 977 99 33 553/6/9977 DOI.7/s-6-8- Ó Birkhäuser Verlag, Basel, 6 Pure and Applied Geophysics Improvement in the Fault Boundary Conditions for a Staggered Grid Finite-difference
More informationUCERF3 Task R2- Evaluate Magnitude-Scaling Relationships and Depth of Rupture: Proposed Solutions
UCERF3 Task R2- Evaluate Magnitude-Scaling Relationships and Depth of Rupture: Proposed Solutions Bruce E. Shaw Lamont Doherty Earth Observatory, Columbia University Statement of the Problem In UCERF2
More informationChallenges in earthquake physics and source imaging
Challenges in earthquake physics and source imaging Jean-Paul Ampuero and Nadia Lapusta (Caltech Seismolab) Main goals and current issues in earthquake dynamics The source imaging inverse problem Parallels
More informationStress transfer and strain rate variations during the seismic cycle
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 19, B642, doi:1.129/23jb2917, 24 Stress transfer and strain rate variations during the seismic cycle H. Perfettini Institut de Recherche pour le Développement/Laboratoire
More informationEarthquake nucleation. Pablo Ampuero Caltech Seismolab
Earthquake nucleation Pablo Ampuero Caltech Seismolab How do earthquakes start? Do small and large earthquakes start differently? Predictive value of earthquake onset and foreshock sequences? Seismological
More informationON NEAR-FIELD GROUND MOTIONS OF NORMAL AND REVERSE FAULTS FROM VIEWPOINT OF DYNAMIC RUPTURE MODEL
1 Best Practices in Physics-based Fault Rupture Models for Seismic Hazard Assessment of Nuclear ON NEAR-FIELD GROUND MOTIONS OF NORMAL AND REVERSE FAULTS FROM VIEWPOINT OF DYNAMIC RUPTURE MODEL Hideo AOCHI
More informationGeophysical Research Letters
Geophysical Research Letters 16 JANUARY 2007 Volume 34 Number 1 American Geophysical Union Toward a more objective determination of seismic hazards Andaman Islands deformation associated with the 2004
More informationHigh Resolution Imaging of Fault Zone Properties
Annual Report on 1998-99 Studies, Southern California Earthquake Center High Resolution Imaging of Fault Zone Properties Yehuda Ben-Zion Department of Earth Sciences, University of Southern California
More informationInfluence of material contrast on fault branching behavior
GEOPHYSICAL RESEARCH LETTERS, VOL. 38,, doi:10.1029/2011gl047849, 2011 Influence of material contrast on fault branching behavior Nora DeDontney, 1 James R. Rice, 1,2 and Renata Dmowska 2 Received 20 April
More informationRecurrence Times for Parkfield Earthquakes: Actual and Simulated. Paul B. Rundle, Donald L. Turcotte, John B. Rundle, and Gleb Yakovlev
Recurrence Times for Parkfield Earthquakes: Actual and Simulated Paul B. Rundle, Donald L. Turcotte, John B. Rundle, and Gleb Yakovlev 1 Abstract In this paper we compare the sequence of recurrence times
More informationDevelopment of a Predictive Simulation System for Crustal Activities in and around Japan - II
Development of a Predictive Simulation System for Crustal Activities in and around Japan - II Project Representative Mitsuhiro Matsu'ura Graduate School of Science, The University of Tokyo Authors Mitsuhiro
More informationby George E. Hilley, J Ramón Arrowsmith, and Elizabeth Stone Introduction
Bulletin of the Seismological Society of America, 91, 3, pp. 427 440, June 2001 Inferring Segment Strength Contrasts and Boundaries along Low-Friction Faults Using Surface Offset Data, with an Example
More informationNumerical study on multi-scaling earthquake rupture
GEOPHYSICAL RESEARCH LETTERS, VOL. 31, L266, doi:1.129/23gl1878, 24 Numerical study on multi-scaling earthquake rupture Hideo Aochi Institut de Radioprotection et de Sûreté Nucléaire, France Satoshi Ide
More informationMechanics of Earthquakes and Faulting
Mechanics of Earthquakes and Faulting Lecture 9, 21 Sep. 2017 www.geosc.psu.edu/courses/geosc508 Rate and State Friction Velocity step test to measure RSF parameters SHS test to measure RSF parameters
More informationSlip-Length Scaling in Large Earthquakes: The Role of Deep-Penetrating Slip below the Seismogenic Layer
Bulletin of the Seismological Society of America, Vol. 98, No. 4, pp. 633 64, August 2008, doi: 0.785/0200709 Slip-Length Scaling in Large Earthquakes: The Role of Deep-Penetrating Slip below the Seismogenic
More information3D modeling of the cycle of a great Tohoku oki earthquake, considering frictional behavior at low to high slip velocities
GEOPHYSICAL RESEARCH LETTERS, VOL. 38,, doi:10.1029/2011gl049308, 2011 3D modeling of the cycle of a great Tohoku oki earthquake, considering frictional behavior at low to high slip velocities B. Shibazaki,
More informationSTRIKE SLIP SPLAY USING DYNAMIC RUPTURE MODELS
STRIKE SLIP SPLAY USING DYNAMIC RUPTURE MODELS Julian Lozos (PEER, UC Berkeley) SWUS GMC Workshop #2, Berkeley, CA, 24 October 2013 Outline Issues in the dynamics of fault branches. Advantages and disadvantages
More informationMarch 2017 SCEC Rupture Dynamics Code Validation Workshop
Presentation for March 1, 2017 SCEC Boardroom Los Angeles, CA March 2017 SCEC Rupture Dynamics Code Validation Workshop Ruth A. Harris (U.S. Geological Survey) Ralph J. Archuleta (UC Santa Barbara) INTRODUCTION
More informationTwo ways to think about the dynamics of earthquake ruptures
Two ways to think about the dynamics of earthquake ruptures (1) In terms of friction (2) In terms of fracture mechanics Scholz describes conditions for rupture propagation (i.e. instability) via energy
More informationPulse like, crack like, and supershear earthquake ruptures with shear strain localization
Click Here for Full Article JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 115,, doi:10.1029/2009jb006388, 2010 Pulse like, crack like, and supershear earthquake ruptures with shear strain localization Eric G.
More informationA new hybrid numerical scheme for modelling elastodynamics in unbounded media with near-source heterogeneities
A new hybrid numerical scheme for modelling elastodynamics in unbounded media with near-source heterogeneities Setare Hajarolasvadi Ahmed E. Elbanna https://www.youtube.com/watch?v=bltx92tuwha MOTIVATION
More informationPulse-like, crack-like, and supershear earthquake ruptures with shear strain localization
JOURNAL OF GEOPHYSICAL RESEARCH, VOL.???, XXXX, DOI:10.1029/, Pulse-like, crack-like, and supershear earthquake ruptures with shear strain localization Eric G. Daub, 1 M. Lisa Manning, 1,2 and Jean M.
More informationMid-Continent Earthquakes As A Complex System
SRL complex earthquakes 5/22/09 1 Mid-Continent Earthquakes As A Complex System Niels Bohr once observed How wonderful that we have met with a paradox. Now we have some hope of making progress. This situation
More informationM 7.0 earthquake recurrence on the San Andreas fault from a stress renewal model
Click Here for Full Article JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 111,, doi:10.1029/2006jb004415, 2006 M 7.0 earthquake recurrence on the San Andreas fault from a stress renewal model Tom Parsons 1 Received
More informationPulse-like, crack-like, and supershear earthquake ruptures with shear strain localization
JOURNAL OF GEOPHYSICAL RESEARCH, VOL.???, XXXX, DOI:.9/, Pulse-like, crack-like, and supershear earthquake ruptures with shear strain localization Eric G. Daub, M. Lisa Manning, and Jean M. Carlson Abstract.
More informationStatistics of Earthquake Stress Drops on a Heterogeneous Fault in an Elastic Half-Space
Bulletin of the Seismological Society of America, Vol. 99, No., pp. 7, June 9, doi:.7/ Statistics of Earthquake Stress Drops on a Heterogeneous Fault in an Elastic Half-Space by I. W. Bailey and Y. Ben-Zion
More informationA constitutive scaling law and a unified comprehension for frictional slip failure, shear fracture of intact rock, and earthquake rupture
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 108, NO. B2, 2080, doi:10.1029/2000jb000123, 2003 A constitutive scaling law and a unified comprehension for frictional slip failure, shear fracture of intact rock,
More informationEffect of Thermal Pressurization on Radiation Efficiency
Bulletin of the Seismological Society of America, Vol. 99, No. 4, pp. 2293 2304, August 2009, doi: 10.1785/0120080187 Effect of Thermal Pressurization on Radiation Efficiency by Jeen-Hwa Wang Abstract
More informationThe critical slip distance for seismic and aseismic fault zones of finite width
The critical slip distance for seismic and aseismic fault zones of finite width Chris Marone 1, Massimo Cocco, Eliza Richardson 1, and Elisa Tinti Istituto Nazionale di Geofisica e Vulcanologia, Rome,
More informationRotation of the Principal Stress Directions Due to Earthquake Faulting and Its Seismological Implications
Bulletin of the Seismological Society of America, Vol. 85, No. 5, pp. 1513-1517, October 1995 Rotation of the Principal Stress Directions Due to Earthquake Faulting and Its Seismological Implications by
More informationQualitative modeling of earthquakes and aseismic slip in the Tohoku-Oki area. Nadia Lapusta, Caltech Hiroyuki Noda, JAMSTEC
Qualitative modeling of earthquakes and aseismic slip in the Tohoku-Oki area Nadia Lapusta, Caltech Hiroyuki Noda, JAMSTEC Constitutive law on the fault: Rate-and-state friction at low slip rates + Potential
More informationPredicted reversal and recovery of surface creep on the Hayward fault following the 1906 San Francisco earthquake
GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L19305, doi:10.1029/2008gl035270, 2008 Predicted reversal and recovery of surface creep on the Hayward fault following the 1906 San Francisco earthquake D. A. Schmidt
More information1/22/2015. High velocity shear experiments with possible implications to earthquake physics
High velocity shear experiments with possible implications to earthquake physics Thanks: Amir Sagy Andrew Madden, David Lockner, Einat Aharonov Harry Green, Jay Finberg, Jefferson Chang, Shalev Siman Tov
More informationDamage Localization, Sensitivity of Energy Release and Catastrophe Transition
Damage Localization, Sensitivity of Energy Release and Catastrophe Transition Y.L.Bai (1), H.L.Li (1), F.J.Ke (1,2) and M.F.Xia (1,3) (1) LNM, Institute of Mechanics, Chinese Academy of Sciences, Beijing
More informationAftershocks are well aligned with the background stress field, contradicting the hypothesis of highly heterogeneous crustal stress
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 115,, doi:10.1029/2010jb007586, 2010 Aftershocks are well aligned with the background stress field, contradicting the hypothesis of highly heterogeneous crustal stress
More informationPREDICTIVE MODELING OF INDUCED SEISMICITY: NUMERICAL APPROACHES, APPLICATIONS, AND CHALLENGES
PREDICTIVE MODELING OF INDUCED SEISMICITY: NUMERICAL APPROACHES, APPLICATIONS, AND CHALLENGES Mark McClure Assistant Professor Petroleum and Geosystems Engineering The University of Texas at Austin Overview
More information3D Finite Element Modeling of fault-slip triggering caused by porepressure
3D Finite Element Modeling of fault-slip triggering caused by porepressure changes Arsalan Sattari and David W. Eaton Department of Geoscience, University of Calgary Suary We present a 3D model using a
More informationEffect of varying normal stress on stability and dynamic motion of a spring-slider system with rate- and state-dependent friction
Earthq Sci (2014) 27(6):577 587 DOI 10.1007/s11589-014-0098-4 RESEARCH PAPER Effect of varying normal stress on stability and dynamic motion of a spring-slider system with rate- and state-dependent friction
More informationOn rate-state and Coulomb failure models
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 105, NO. B4, PAGES 7857 7871, APRIL 10, 2000 On rate-state and Coulomb failure models J. Gomberg U.S. Geological Survey, Center for Earthquake Research and Information,
More informationGPS Strain & Earthquakes Unit 5: 2014 South Napa earthquake GPS strain analysis student exercise
GPS Strain & Earthquakes Unit 5: 2014 South Napa earthquake GPS strain analysis student exercise Strain Analysis Introduction Name: The earthquake cycle can be viewed as a process of slow strain accumulation
More informationSpectral element modeling of spontaneous earthquake rupture on rate and state faults: Effect of velocity-strengthening friction at shallow depths
JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 113,, doi:10.1029/2007jb005553, 2008 Spectral element modeling of spontaneous earthquake rupture on rate and state faults: Effect of velocity-strengthening friction
More informationSan Francisco Bay Area Earthquake Simulations: A step toward a Standard Physical Earthquake Model
San Francisco Bay Area Earthquake Simulations: A step toward a Standard Physical Earthquake Model Steven N. Ward Institute of Geophysics and Planetary Physics, University of California, Santa Cruz, CA,
More informationFrictional Properties on the San Andreas Fault near Parkfield, California, Inferred from Models of Afterslip following the 2004 Earthquake
Bulletin of the Seismological Society of America, Vol. 96, No. 4B, pp. S321 S338, September 2006, doi: 10.1785/0120050808 Frictional Properties on the San Andreas Fault near Parkfield, California, Inferred
More informationSimulating Gravity, Potential, and Sea Level Change with Topologically Realistic Earthquake Fault System Models
Simulating Gravity, Potential, and Sea Level Change with Topologically Realistic Earthquake Fault System Models Kasey Schultz February 3, 2014 Abstract Following the success of the GRACE mission, NASA
More informationLABORATORY-DERIVED FRICTION LAWS AND THEIR APPLICATION TO SEISMIC FAULTING
Annu. Rev. Earth Planet. Sci. 1998. 26:643 96 Copyright c 1998 by Annual Reviews. All rights reserved LABORATORY-DERIVED FRICTION LAWS AND THEIR APPLICATION TO SEISMIC FAULTING Chris Marone Department
More informationThe Bridge from Earthquake Geology to Earthquake Seismology
The Bridge from Earthquake Geology to Earthquake Seismology Computer simulation Earthquake rate Fault slip rate Magnitude distribution Fault geometry Strain rate Paleo-seismology David D. Jackson djackson@g.ucla.edu
More informationFault Specific, Dynamic Rupture Scenarios for Strong Ground Motion Prediction
Fault Specific, Dynamic Rupture Scenarios for Strong Ground Motion Prediction H. Sekiguchi Disaster Prevention Research Institute, Kyoto University, Japan Blank Line 9 pt Y. Kase Active Fault and Earthquake
More informationJOURNAL OF GEOPHYSICAL RESEARCH, VOL.???, XXXX, DOI: /,
JOURNAL OF GEOPHYSICAL RESEARCH, VOL.???, XXXX, DOI:10.1029/, 1 2 Self-similar slip pulses during rate-and-state earthquake nucleation Allan M. Rubin 3 4 Department of Geosciences, Princeton University,
More informationImpact of Friction and Scale-Dependent Initial Stress on Radiated Energy-Moment Scaling
Impact of Friction and Scale-Dependent Initial Stress on Radiated Energy-Moment Scaling Bruce E. Shaw Lamont Doherty Earth Observatory, Columbia University, New York, USA The radiated energy coming from
More informationNumerical approximation of rate-and-state friction problems
Preprint No. 1 Numerical approximation of rate-and-state friction problems Elias Pipping Ralf Kornhuber Matthias Rosenau Onno Oncken April, 2015 Project B01 This research has been funded by Deutsche Forschungsgemeinschaft
More informationCriticality of Rupture Dynamics in 3-D
Pure appl. geophys. 157 (2000) 1981 2001 0033 4553/00/121981 21 $ 1.50+0.20/0 Criticality of Rupture Dynamics in 3-D RAUL MADARIAGA 1 and KIM B. OLSEN 2 Abstract We study the propagation of seismic ruptures
More informationLecture 20: Slow Slip Events and Stress Transfer. GEOS 655 Tectonic Geodesy Jeff Freymueller
Lecture 20: Slow Slip Events and Stress Transfer GEOS 655 Tectonic Geodesy Jeff Freymueller Slow Slip Events From Kristine Larson What is a Slow Slip Event? Slip on a fault, like in an earthquake, BUT
More informationA possible mechanism of M 9 earthquake generation cycles in the area of repeating M 7 8 earthquakes surrounded by aseismic sliding
LETTER Earth Planets Space, 63, 773 777, 2011 A possible mechanism of M 9 earthquake generation cycles in the area of repeating M 7 8 earthquakes surrounded by aseismic sliding Takane Hori 1 and Shin ichi
More informationMaterials and Methods The deformation within the process zone of a propagating fault can be modeled using an elastic approximation.
Materials and Methods The deformation within the process zone of a propagating fault can be modeled using an elastic approximation. In the process zone, stress amplitudes are poorly determined and much
More informationGeophysical Journal International
Geophysical Journal International Geophys. J. Int. (2011) 186, 1389 1403 doi: 10.1111/j.1365-246X.2011.05117.x Shallow slip deficit due to large strike-slip earthquakes in dynamic rupture simulations with
More informationARMA INTRODUCITON
ARMA 14-143 Insights into dynamic asperity failure in the laboratory Selvadurai, P.A. University of California, Berkeley, CA, USA Glaser, S.D. University of California, Berkeley, CA, USA Copyright 2014
More informationThe San Andreas Fault Observatory at Depth: Recent Site Characterization Studies and the 2.2-Km-Deep Pilot Hole
The San Andreas Fault Observatory at Depth: Recent Site Characterization Studies and the 2.2-Km-Deep Pilot Hole Steve Hickman and Bill Ellsworth (USGS) Mark Zoback (Stanford University) and the Pre-EarthScope
More informationCOULOMB STRESS CHANGES DUE TO RECENT ACEH EARTHQUAKES
COULOMB STRESS CHANGES DUE TO RECENT ACEH EARTHQUAKES Madlazim Physics Department, Faculty Mathematics and Sciences of Surabaya State University (UNESA) Jl. Ketintang, Surabaya 60231, Indonesia. e-mail:
More informationRheology III. Ideal materials Laboratory tests Power-law creep The strength of the lithosphere The role of micromechanical defects in power-law creep
Rheology III Ideal materials Laboratory tests Power-law creep The strength of the lithosphere The role of micromechanical defects in power-law creep Ideal materials fall into one of the following categories:
More informationAndrews D. J. ( 1973 ) : A numerical study of tectonic stress release by underground explosions, Bull. Seism. Soc. Am., 63, No. 4, pp.
Aki K. ( 1979 ) : Characterization of barriers on an earthquake fault, J. Geophys. Res., 84, No. B11, pp. 6140 6148 Andrews D. J. ( 1973 ) : A numerical study of tectonic stress release by underground
More informationKnowledge of in-slab earthquakes needed to improve seismic hazard estimates for southwestern British Columbia
USGS OPEN FILE REPORT #: Intraslab Earthquakes 1 Knowledge of in-slab earthquakes needed to improve seismic hazard estimates for southwestern British Columbia John Adams and Stephen Halchuk Geological
More information